When we asked American astronomy professor Andrea Ghez, winner of the 2020 Nobel Prize in Physics on Tuesday (6), how she explains a black hole to a child, she replies: “An object whose gravitational force is so intense that nothing can escape, not even the light “.
The definition does not always satisfy the curiosity of its interlocutors.
- WEB STORIES: Check out Nobel stories and curiosities
“Very few people understand what a black hole is, but many people are fascinated by them,” Andrea Ghez told AFP from California, an hour after becoming the fourth woman to receive the physics award.
Scientist Andrea Ghez, winner of the Nobel Prize in Physics in 2020 and the fourth woman to be awarded in the category since 1901. – Photo: Jan Norden, The Royal Swedish Academy of Sciences / Twitter Nobel Prize
This year, his group of researchers celebrated the 25th anniversary of the beginning of his work, which culminated, using gigantic telescopes in Hawaii and countless calculations, in the measurement of the supermassive black hole in the center of the Milky Way, called Sagittarius A *.
“It is very difficult to conceptualize a black hole,” she agrees. “The laws of physics near a black hole are so different from those operating on Earth, that you have no intuition for the things you are looking for.”
“I can think mathematically, abstractly, but forming an image is very difficult, because space and time are mixed.”
The way to “see” a black hole, by definition invisible, is to observe the objects that rotate around and reveal the presence of the giant.
In that case, the stars. Andrea Ghez confirms that after 25 years she has a very accurate mental map of the stars that revolve around Sagittarius A *.
“The stars are like children whose names we all know, but they change a little each year,” says the astronomer.
She knows exactly where the star S2 is located, whose 16 years of orbit around the black hole she mapped accurately. “We are watching the star closely.”
Physics Nobel Prize goes to three scientists who made discoveries about black holes
Another neophyte question: is it true, as the Swedish academy writes, that no one would feel anything if they fell into a black hole?
“We would not survive. If you fell with your feet forward in a black hole, the first thing that would happen is that the gravitational pull would be much stronger on your feet than on your head, then you would be torn apart. Then we would feel nothing. because we would no longer exist, we would not survive, we would disintegrate into our fundamental elements “.
“I wouldn’t like that,” he concludes.
Meet the Nobel Prize winners 2020
Andrea Ghez, PhD from Caltech (1992), has been at the University of California at Los Angeles since 1994, where he co-directs the Galactic Center. She firmly believes that many mysteries of black holes will be unraveled even more in her life.
“This is an area of physics where the pace of discovery is accelerating, because technology is evolving at high speed. And, frankly, we know so little.”
Two years ago, Canadian physics Donna Strickland won the Nobel Prize in Physics and, before them, only two women won, in 1963 (Maria Goeppert Mayer) and 1903 (Marie Curie). Against more than 200 men.
“The field has been dominated by men for a long time, but more and more women are joining the discipline. I am very happy to be able to be a model for young women who are thinking of starting,” concludes the scientist.